Door operating means for bottom dump wagons



June 1966 H. H. BOWEN E 3,254,920

DOOR OPERATING MEANS FOR BOTTOM DUMP WAGONS 2 Sheets-Sheet 1 Filed June 12, 1964 INVENTORS H. 30 WEN E M/L B. L EE BY P/CHARD 144 L Z/TT/PELL ATTORNEYS AMP/w June 7, 1966 H. H. BOWEN ETAL 3,254,920

DOOR OPERATING MEANS FOR BOTTOM DUMP WAGONS Filed June 12, 1964 2 Sheets-Sheet a I I. E 3 2% m gfl' INVENTORS 144m A Bows/v EM/L 5. LEE

BY R/cHA/w M4 LUTT/PELL WWW! United States Patent 3,254,920 DOOR OPERATING MEANS FOR BOTTOM DUMP WAGONS Harry H. Bowen, Pelcin, and Emil E. Lee and Richard W. Lnttrell, Morton, IlL, assignorsto Caterpillar, Tractor (30., Peoria, IlL, a corporation of California Filed June 12, 1964, Ser. No. 374,756 6 Claims. (Cl. 298-35) The present invention relates to improvements in material haulage bodies and the like and more particularly to new and improved means for opening and closing the doors of bottom dump haulage bodies.

In fulfilling present day requirements for haulage vehicles of increased capacity, it has been necessary to design increasingly larger bodies whose length may be forty feet or more. Bottom dump bodies of the type disclosed herein are constructed to provide laterally swinging bottom doors meeting at substantially the longitudinal center of the body and are simultaneously opened and closed by mechanisms which include a hydraulically powered motor and a system of sheaves through which is trained a cable connected to the motor and to each of the doors.

It is usual practice to provide a single motor mounted on one of the longitudinal sides of the body and have the cable trained through sheaves which are located so that the cable defines a path extending longitudinally and laterally of the body with the ends of the cable being connected to the inner longitudinal corners of each door. The amount of cable required in the above described door actuating mechanisms may reach a hundred feet or more, and the cable path which is defined by the sheaves changes its direction several times thus subjecting a plurality of discrete portions of the cable to severe reversals of stresses.

When it is considered that haulage vehicles of the type disclosed herein are designed to carry one hundred tons or more and this load is supported by the doors defining the bottom of the haulage compartment, the associated cables are subjected to rather high values of tensile stresses which have the effect of causing elongation of the cable. It is to be appreciated that the unit elongation of the cable multiplied by the entire length of the cable yields a total elongation of an amount sufficient to cause partial opening of the doors when the haulage compartment is filled to capacity.

In solving the problems of cable elongation and reversal of stresses, this invention provides a pair of hydraulic motors, mounted on the rearward and forward ends of the haulage vehicle, associated with short'lengths of cable trained through appropriately located sheaves with the location of the sheaves being so chosen that the stress reversal imparted to the cable is held to a minimum. This invention also provides a length of chain secured to each inner corner of the doors and to the cable ends in order to resist destructive forces occasioned by cascading of the load downwardly when the doors are open. It is of utmost importance in haulage vehicles of the bottom dump type to insure that the inner longitudinal ends of each door are caused to move at the same rate thereby precluding twisting or bending of the doors. This invention fulfills this requirement by providing a conventional hydraulic circuit which simultaneously actuates the door operating motors and accordingly effects closing and opening the doors at the same rate.

Accordingly, it is an object of this invention to provide a new and improved door actuating mechanism for a material haulage body.

Another object of this invention is to provide a door actuating mechanism for a bottom dump haulage body which requires a very short length of cable.

A further and more specific object of this invention is to provide a training path for the cable which minimizes the number of cable-training sheaves and the stress reversal of the cable.

The exact nature of this invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification relating to the. drawings in which:

FIG. 1 isa side elevation of a bottom dump wagon incorporating the improved door actuating mechanism of this invention;

FIG. 2is an enlargedfragmentaryperspective of the forward end of the dump body shown in FIG. 1 illusvtrating the actuating mechanism of this invention;

FIG. 3 is also an enlarged fragmentary perspective of the front end of-the wagon showing a modification of the structure shown in FIG. 2;

FIG. 4 is a further enlarged fragmentary view of FIG. 3 viewed in the direction of the plane IV-IV;

FIG. 5 is a side view of FIG. 4 with certain parts broken away to show the details of construction.

Referring to FIG. 1 the bottom dump wagon incorporating this invention comprises an elongated generally rectangular material containing body 1t) supported on a pair of forward wheels 12 and a pair of rearward wheels 14. Discharge of material from the body 19 is accomplished by providing a pair of doors 16 extending the entire length of the compartment with each door hingedly connected by a plurality of longitudinaliy spaced hinges 18 to the lower longitudinal sides of the body 13. Each door is rectangular in shape and their respective free ends are brought into abutting engagement substantially along the line constituting the longitudinal median of the body. A pair of door actuating mechanisms 20, one of which is mounted on the forward wall of-the body and the other'on the rearward wall of the body, are connected by means of chain-cable tension devices to effect opening and closing of the doors 16.

Referring now to FIG. 2 which shows the forward one of the actuators 20 in greater detail, it is seen that an hydraulically operated motor in the form of a jack mechanism 22 is pivotally secured on. a bracket member 24 by means of a pivot pin 26 to extend transversely across the front end of the body. As is common, the hydraulic jack includes a projecting rod 28 on the end of which is secured, in any suitable manner, a generally rectangular mounting flange 30 to which is secured a sheave block 32 having a pair of co-axial sheaves 34 and 36 rotatably mounted on a shaft 38.

An outboard support which constrains the sheave block 32 to move in an arcuate path is provided. Such outboard-support includes a pair of link members 44 spaced to receive the sheave block 32 therebetween and being pivotally connected to the shaft 38 at one end and the other end freely mounted on a stub shaft 46 which is rigidly secured to the wall of the body 10. It is apparent from the foregoing construction that extension and retraction of the piston rod 28 causes the hydraulic jack 2-2 and the sheave block 32 to pivot about the pivot pin 26 as the jack 22 is extended or retracted.

Another pair of sheaves 48 and 50 being co-planar, respectively, with the sheaves 34 and 36 are mounted for rotation on a shaft 52 which is supported in a bracket 54. This bracket comprises a rectangular plate 56 secured to the wall of the body 10 and a U-shaped strap (shown partly broken away) 58 fixed to the plate 56. As will be apparent by inspection of FIG. 2, the bracket 54- permits free rotation of the sheaves 48 and 50. Each of the doors 16 include enlarged bosses 60 (only one of which is clearly shown in FIG. 2) within which are secured outwardly extending pins 62 each of which have radially enlarged terminal portions 64.

In order to achieve opening and closing of the doors 16 by means of the above described hydraulic jack and associated sheave blocks, a tension device is provided which comprises a single cable 66 reaved in a manner hereinafter set forth and a pair of chains 68. The central portion of the cable 66 is fixed to the body 10 by bracket member 69 secured to the body 10. As shown, the bracket member 69 comprises a pair of laterally spaced plates 70 between which is mounted a clamping member 72 which is pivotally connected by means of apin 74 extending through the member 72 and the plates 70. The cable 66 has its central portion fixed within the clamping member 72 with the free ends trained about the sheaves 34 and 36 and the sheaves 48 and 5t) and extending downwardly a short distance beyond the sheaves 48 and 50. It is to be appreciated that the cable 66 need not comprise a single strand anchored to the body 16 as described, but may comprise two short strands each of which may be secured to the body in'any suitable manner, for example, by using a thimble and a bolt anchor. On each of the free ends of the cable 66 conventional clamping members 76 are secured which are adapted to have the chains 68 also secured thereto to constitute a unitary tension device. The lower ends of the chains are connected to a U-shaped strap 78 located between the portion 64 and the boss 60.

When'the doors 16 are opened to discharge material from the body, the jacks 22 are retracted causing the cable ends and the chains 68 to travel downwardly and slightly outwardly, thus locating the chains below the bottom of the body. The cables, however, are under all circumstances, located above the bottom of the body. In this manner the abrasive action of the material being discharged is transmitted to the chains which are made of a steel alloy that is highly abrasion resistant. Accordingly trouble-free operation over a long period of time is achieved.

Simultaneous energization of the actuating mechanisms 20 is obtained by incorporating -a hydraulic circuit, part of which is shown in FIG. 2 'and is identified by the numeral 80, that is connected to each of the jacks 22 in such a manner that the jacks are extended and retracted at the same time to effect, respectively, opening and closing of the doors 16. The manner in which the jacks are connected to fulfill this function and the hydraulic controls for achieving such operation are conventional in the art and do not form part of this invention, therefore, detailed illustration and description thereof is not believed to be necessary.

Operation of the above described embodiment is as follows: Assuming that the body 10 is filled with material desired to be dumped, the operator actuates the appropriate control to cause simultaneous retraction of the jacks 22. Such retraction moves the sheave blocks 32 to the right as viewed in FIG. 2 in an arcuate path, with its center being defined by the axis of the stub shaft 46, causing the cable 66 and the associated sheaves 34, 36, 48 and 50 to rotate permitting the ends of the cable 66 to move downwardly. As a consequence the doors 16 rotate in opposite directions about their hinged connections 18 opening the doors and allowing the material in the body to be discharged. When it is desired to close the doors, the operator manipulates the appropriate hydraulic control extending the jacks 22 and again causing rotation of the sheave block 32 about the stub shaft 46 drawing the cable and the chains upwardly until the doors 16 are closed as shown in FIG. 2.

The modification shown in FIGS. 3 to 5 is identical in construction to the preferred embodiment with the exception that the sheave block 32 is supported to follow a rectilinear path when the jack 22 is actuated. In this embodiment the sheave block 32 is guided for rectilinear movement by means of an elongated guide member 82 rigidly mounted to the wall of the body 10. The guide member 82 comprises elongated blocks 84 secured to the body 10, preferably by welding, and rail members 86 secured to each of the blocks 84 by means of bolts 88. As shown in FIG. 4, the rails 86 extend laterally outwardly relative to the blocks 84 thereby constituting a longitudinal guideway for the sheave block 32. A pair of laterally spaced slotted holders 90 are mounted on the inner side plate of the sheave block 32 and are slotted to receive slider bearing 92 being captively retained in the slots by retaining plates 94- bolted to the end surfaces of the holders 90. The slider bearings are formed with generally rectangular slots 96 which slidably engage the outwardly extending portions of the rails 86. Thus according to this construction during extension or retraction of the jack 22, the traveling sheave block 32 is supported and guided for rectilinear movement effecting, respectively, closing and opening of the doors 16.

Although the bracket member 24 is shown to be oriented so that the pin 26 is extending generally vertically, it is to be appreciated that it may assume the orientation shown in FIG. 1.

As a result of this invention, it is seen that a very compact and simple mechanism is provided for operating the doors on a bottom dump wagon. By providing an actuating mechanism at the opposite ends of the body, very short cables can be used thus substantially reducing the total elongation of the cable. In addition, employing chains of sufiicient length at the ends of the cable serves to lengthen the life of the tension members far beyond that which would be expected if the tension members were made wholly from cables.

We claim:

1. In a bottom. dump wagon, an elongated body; a pair of doors defining the bottom Wall of said body and mounted for downward and outward movement relative to said body; said doors closing along a line defining the longitudinal median of said body; hydraulic jack mechanisms mounted on each end of said body and oriented so that their line of action is transverse relative to the longitudinal median of said body; a sheave block, rotatably supporting a pair of adjacent sheaves, fixed to the rod of each jack mechanism; an outboard support movably supporting each sheave block during extension and extraction of said jack mechanism; stationary sheave blocks, each of which include adjacent sheaves being co- I planar with the first mentioned sheaves, mounted on each end of-said body and located below mentioned line of action of said jack mechanisms; and cable-chain tension devices associated with each of the sheaves and trained thereabout for connection to the inner longitudinal corners of said door in order to transfer the motion of said jack mechanisms to said doors to thus effect opening and closing of said doors, said chains constituting the terminal portion of said tension devices which are connected to the doors.

2. In a bottom dump wagon body which includes a pair of cooperating elongated doors pivotally mounted on the bottom lateral sides of said body to define, when closed, the bottom wall of the body and wherein means are provided for opening and closing the doors: said means comprising transversely extending hydraulic jacks mounted on each end of said body, said jacks being operable to be simultaneously extended and retracted, a sheave block including a first pair of adjacent axial aligned sheaves secured to the rod of each jack, support means for supporting and constraining said sheave block as the jacks are actuated to define an arcuate path, a second pair of sheaves each one of which is co-planar with said first pair of sheaves and being rotatably mounted below said jacks, said second pair of sheaves being located so that a peripheral portion thereof is located vertically above the longitudinal median of the body, tension devices comprising a cable portion and chain portions, said cable portion being reaved through said sheaves and said chain portions extending from the ends of said cable which terminate closely adjacent said second pair of sheaves with said chain portions extending from the termination of said cable for securement to the inner longitudinal ends of said doors.

3. In a bottom dump wagon body which includes a pair of cooperating elongated doors pivotally mounted on the bottom lateral sides of said body, a pair of hydraulic jacks one of which is mounted on the forward and the other on the rearward wall of said body, a sheave block including a pair of adjacent axial aligned sheaves secured to the end of the rod of each jack, an outboard support having cooperating parts on each of said sheave block and on said body for guiding said sheave block in a rectilinear path as said jacks are actuated, another pair of sheave blocks each of which have sheaves which are co-planar with the first mentioned sheaves and being rotatably mounted below said jacks, a tension device comprising a cable portion and chain portions, said cable portion being reaved through said sheaves and said chain portions extending from the ends of said cable which terminate closely adjacent said second mentioned pair of sheaves, said chain portions extending from the termination of said cable and being attached to the inner longitudinal ends of said doors.

4. An apparatus for operating the doors of a bottom dump wagon comprising, an elongated generally rectangular body, a pair of doors pivotally mounted on the bottom of said body for movement downwardly and outwardly relative to said body when open, said doors when closed define the bottom wall of said body, pairs of sheave blocks mounted on the forward and rearward wall of said body, each of said sheave blocks including coplanar sheaves which are adapted for reaving a cable, means for effecting lateral movement one of said sheave blocks relative to the other, cable means having a central portion fixed to said body and reaved through said sheave blocks so that the ends terminate slightly beyond the fixed one of said sheave blocks, a pair of chains having one end secured to the terminal ends of said cable and the other end secured to the inner ends of the doors, wherein movement of said movable sheave block in one direction causes paying out of said cable and con-sequent opening of the doors and movement of the movable sheave block in the other direction elTects paying in of the cable and closing of the doors.

5. In a bottom dump wagon, an elongated body, forward and rearward walls, a pair of doors defining the bottom wall of said body and mounted for downward and outward movement relative to said body, said doors closing substantially along a line defining the longitudinal median of said body, hydraulic motors operably mounted on said forward and rearward walls, and tension devices comprising cable and chain portions with the chain portions connected to said doors and constituting the terminal portions of said tension devices, said cable portions being trained on sheaves to be translated by said motors for transmitting the output of said motors to said doors and thus etr'ect opening and closing thereof, said cable portions being of a length sufiicient to provide that said chain portions do not engage said sheaves.

6. In a bottom dump wagon, an elongated body, forward and rearward walls, at least one door pivotally mounted at a bottom portion of said body, said door defining in part the bottom wall of said body, said door closing substantially along a line defining the longitudinal median of said body, hydraulic motors operably mounted on said forward and rearward walls and tension devices comprising cable and chain portions with the chain portions connected to said door and constituting the terminal portion of said tension devices, said cable portions being trained on sheaves to be translated by said motors for transmitting the output of said motors to said door and thus eifect opening and closing thereof, said cable portions being of a length sufiicient to provide that said chain portions do not engage said sheaves.

References Cited by the Examiner UNITED STATES PATENTS 1,984,876 12/1934 Jett 298-35 2,237,299 4/ 1941 Benbow.

2,575,355 11/1951 Mork 29835 2,663,231 12/1953 Wood 298-30 X 2,723,878 11/1955 Rockwell -250 X BENJAMIN HERSH, Primary Examiner.

R. I. JOHNSON, Assistant Examiner. 

6. IN A BOTTOM DUMP WAGON, AN ELONGATED BODY, FORWARD AND REARWARD WALLS, AT LEAST OEN DOOR PIVOTALLY MOUNTED AT A BOTTOM PORTION OF SAID BODY, SAID DOOR DEFINING IN PART THE BOTTOM WALL OF SAID BODY, SAID DOOR CLOSING SUBSTANTIALLY ALONG A LINE DEFINING THE LONGITUDINAL MEDIAN OF SAID BODY, HYDRAULIC MOTORS OPERABLY MOUNTED ON SAID FORWARD AND REARWARD WALLS AND TENSION DEVICES COMPRISING CABLE AND CHAIN PORTIONS WITH THE CHAIN PORTIONS CONNECTED TO SAID DOOR AND CONSTITUTING THE TERMINAL PORTION OF SAID TENSION DEVICES, SAID CABLE PORTIONS BEING TRAINED ON SHEAVES TO BE TRANSLATED BY SAID MOTORS FOR TRANSMITTING THE OUTPUT OF SAID MOTORS TO SAID DOOR AND THUS EFFECT OPENING AND CLOSING THEREOF, SAID CABLE PORTIONS BEING OF A LENGTH SUFFICIENT TO PROVIDE THAT SAID CHAIN PORTIONS DO NOT ENGAGE SAID SHEAVES. 